A driver travelling at 90 km/h needs 0.75 s to react to a hazard. How far does the car travel before the driver starts to brake?
Answer and explanation
Correct answer: C. 18.75 m
- Step 1: Speed in m/s = 90 ÷ 3.6 = 25 m/s. Step 2. Distance = 25 × 0.75 = 18.75 m. Answer: 18.75 m. Why not the others: 67.5 m results from having treated km/h as m/s. 9.375 m results from having halved the reaction time. 37.5 m results from having doubled the reaction time.
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